System Boilers

System boilers are very similar to gas (aka conventional/heat-only/traditional) boilers. It directly heats your central heating system, producing hot water stored in the hot water cylinder – which in turn is usually tucked away inside an airing cupboard. Like combination boilers it’s a little more compact than a traditional boiler, thanks to its mainly pre-built components. That means there’s no need for an expansion cistern or expansion feed.

How a system boiler works

Like gas boilers, system boilers work on the ‘stored hot water’ principle. The standout difference is that they come made with all their major components built in, so they take up less space and are easier to install. You’ll still need to have a cold water tank, unless the hot water cylinder is pressured.

A system boiler will suit your home if…

It’s a large and modern family home, with as much demand for space as there is for hot water. Keep a busy family happy at peak times with pre-programmed controls and the capacity to serve several users at once.

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How to choose the right system boiler:

  • Are you pushed for space? System boilers are rather more bulky than combination types
  • Limited hot water: because of the finite size of your hot water tank, be sure that your household aren’t all going to want hot, luxuriant baths at the same time
  • Be organised: with the clocks going back and forth during the year, it’s easy to lose track of the change in seasons – and the programmable timings
  • Energy efficiency: the hot water cylinder must be well-insulated, or else it leaks valuable heat into its surroundings

When choosing a new system boiler, ask yourself:

  • How many people are in my household?
  • How much hot water am I expecting the household to use?
  • What brands are on offer, and which are the most reliable?
  • Do I want an eco-efficient model so I can lower my bills? (All boilers are rated A-G, with A the most efficient)
  • What’s my budget – will upfront or monthly payments be more suitable?

Benefits of a System Boiler

Hot water on demand: An electric water heater can be added to the hot water cylinder, giving you hot water outside of programmed times.

Extra loft space: System boilers can be used with pressurised cylinders, so you don’t need to have a cold water tank, a feed or an expansion tank in the loft.

Easier installation: Pre-built components make installation a relative doddle, meaning our engineers can be in and out of your house in a flash and without creating any chaos at all.

More than 1 hot tap: With a system boiler, unlike a combi boiler, you won’t experience any drop in pressure if there is more than one hot water tap being used at any one time, since it comes directly from storage.

Plenty to go round: As long as there’s enough water in the tank, multiple users can enjoy the hot water – and the electric water heater can bridge any gaps.

Keeps bills down: A built-in pump means a fast response, which means you burn less gas and reduce your fuel bills.

Costs and finance options for system boiler Installation

Paying upfront is a popular choice if monthly payments aren’t right for you. It can work out cheaper in the long term, since the price of the unit and installation is wrapped up in a one-off sum – which could be £600-£1500.

With repayment options of three to eight years on offer, flexible finance will suit you if you prefer to spread the upfront cost of your system boiler, installation and maintenance (depending on the brand and model).

This option gives you a controlled cost that fits around your lifestyle and budget². No hidden charges, no upfront costs. The price of installation is included in the price, along with a full initial and ongoing system check, 24/7 emergency cover and other services.